Source: The Mercury, 27 September, 1996, p.85


Computer right so far - its the Kangaroos

   By TED HOPKINS
   THE computer seems to 
like it at the business end of the 
season. So far it has tipped the 
winner for each final. If North 
wins, it will make it nine out of 
nine for Swinburne University 
maths professor Stephen 
Clarke, who is the writer of the 
program.

    It calculates North has a 
63% chance of beating Sydney 
by an expected margin of 13 
points. This margin includes a 
six-point home ground advan-
tage made up of four points to 
North and minus two points 
for Sydney.

   A ground advantage of one 
goal is around the middle  
range for teams competing at 
the G. It's nowhere near the 
kind of margins enjoyed by 
interstate teams in their home 
finals, but in a close game six 
points can mean the difference 
between winning and losing.

   What the computer is 
effectively saying is that if the 
game were played on neutral 
territory, North is a seven-
point better side than Sydney, 
based purely on rating the 
scores of each team, with a 
weighting given to more re-
cent games.

   The computer does not take 
into account player selections, 
injuries or tribunal reports.

   While there seems to be a 
perception that Sydney is near 
to a certainty beaten, the 
computer doesn't think so. A 
63% chance of North winning 
still gives the Swans a 37% 
look in, which is a fair tilt at 
the flag.

   There is another level of data 
not fed into the computer 
which also gives the Swans a 
fair go. They have the equal 
best defence in the compe-
tition and have been credited 
with the most number of kicks 
of any team this season.

   With the exception of a  
shaky start and its game 
against Fremantle in Perth, 
Sydney has either won, or has 
been very competitive when it 
has travelled interstate.

   These are all the signs of a 
genuine premiership con-
tender.

   But there are also other 
"success indicators" to take 
into account, which is why 
North looms as the premier-
ship favourite.

   During the finals the tempo 
and the pressure increases. 
"Easy" possessions and clear 
space are harder to find. When 
the heat is on, it follows that 
the team with the proven  
ability to win the hard ball 
contests on the ground and in 
the air, and then deliver long 
and effectively, has the advan-
tage.

   North should win because 
percentages count in a grand 
final. Clear possessions are 
luxuries, if you can get 'em!


Where to next?

Student Questions for this article
Teacher Discussion of this article
Index - Related articles
Index - Chance and Basic Probability
Numeracy in the News - Main Index